Soon after becoming an undergraduate he joined the little band of young men known as 'Methodists', and remained a sympathiser with the Wesleys for several years, until differences of opinion on the Moravian doctrines led to their separation.
Broughton's first clerical duty was at Cowley, near Uxbridge, and he was curate at the Tower of London in 1736.
In 1741 he was appointed lecturer at Allhallows, Lombard Street, and two years later was elected secretary to the Society for Promoting Christian Knowledge, a position which he retained until his death.
A portrait of Broughton hangs in the board-room of the Society for Promoting Christian Knowledge.
Two outspoken sermons of his attained great popularity: The Christian Soldier, or the Duties of a Religious Life recommended to the Army, which was preached in 1737, printed in 1738, and reached its twelfth edition in 1818, a Welsh translation having appeared in 1797; and A Serious and Affectionate Warning to Servants, occasioned by the brutal murder of a mistress by her male servant aged only 19, and issued in 1746, ninth edition 1818.